In tool turrets, as disclosed in German 38 14 595 A1, the precision of positioning of the turret head can be diminished if the turret is mounted on a reverse spindle lathe (turning machine). During operation of a tool held by the reverse spindle, a cutting force stress is exerted on the turret head which causes the turret head to be lifted from the housing. Such force is greater than the differential between the power exerted by the piston either operating or forming the interlocking or clamping member by the toothed rim of the tool turret, and the reactive force working on the turret head in opposition to this force. When the bearing receiving axial forces from the tool turret has a certain degree of play, the position of the tool turret can be modified. The play leads to corresponding imprecisions in its positioning, and thus, in the processing of workpieces.
The production of hydraulic forces by use of pistons in the tool turret and for axial movement of shafts is disclosed in German Patent No. 40 18 543 C1, wherein the shafts support gear wheels which must be brought into and out of contact with other gear wheels.